1. Field of the Invention
The invention relates to a bioreactor, especially a plug flow bioreactor, which has a long-shaft agitator for thoroughly mixing a biomass with a high solids content that is to be degassed in a fermentation chamber.
2. Description of the Prior Art
The use of bioreactors in biogas plants is well known and has proven effective. In this connection, bioreactors are used for the fermentation of biowaste, green waste, food waste or the like, which has a high solids content, for example, more than 40%, without the addition of liquid manure. The resulting fermentation is dry mesophilic or thermophilic fermentation at moderate temperatures, for example, 37-41° C. or 50-60° C.
In addition, a plug flow bioreactor can be continuously charged, which is equivalent to a large input of biomass to be fermented, which in turn results in a high gas yield. The agitator ensures optimal degassing and a uniform temperature distribution, and the results plug flow ensures a well-defined residence time of the substrate in the bioreactor.
Plug flow bioreactors of the type under discussion are comparatively complicated in their design and normally require a large number of additional buildings, for example, operations buildings, gas accumulators, etc.
The capital expenses of biogas plants operated in this way are correspondingly high.